Automatic train-control system



W. K. vHOWE.

7 AUTOMATIC TRAIN CONTROL .SYSTEM. APPLICATION FILED JULY 3. 1916. RENEWED JUNE 25, 192:.

1,405,377. Patented Jan. 31,1922,

m 1%;:1177/1111, Fl 95 INI/EIVTOR i, ,2,- T XWTTORNEY g wmrnaor x. HOWE, or nocnnsrnn, NEW YORK, ASSIGN'OR TO GENERAL RAILWAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF NEW YORK.

AUTOMATIC TRAIN-CONTROL SYSTEM.

iaoaaw.

Specification of Letters Patent.

Patented Jan. 31, 1922.

Application filed July 3, 1916, Serial No. 107,357. Renewed June 25, 1921. Serial No. 480,462;

To all whom it may concern Be it known that l, WINTHRO? K. Howe, a citizen of-the United States, and a resident of the city of Rochester, in the county of Monroe and State of New York, have invented new and useful Improvements in Automatic Train-Control Systems, of which the followingis a specification.

This invention relates to automatic train control systems and more particularly to such systems which act to control the speed of the train.

In my prior application, Serial No. 38,132, filed July 6, 1915, I have disclosed a system for automatically controlling the speed of railway trains, in which, generally stated, the speed of the train is controlled by the c'o-operation of a device thereon indicating the actual speed of said train with another device, speci cally a rotary cam, which is moved in accordance with the distance traveled by the train and which indicates the permissive speed for the train at each point in its travel, said cam being arranged to be connected to a pair of wheels of the train by means of suitable gearing. In view of'the important duty performed by this gearing, it is desirable to make provision for checking its integrity. and the primary object of this invention is a construction and arrangement of parts whereby each time the speed control apparatus is so controlled as to connect the cam above mentioned to the wheels of the vehicle, it is necessary for this gearing to be intact and operating properly in order to permit the vehicle to proceed.

Other objects andadvantages will appear as the description of the invention progresses, and the novel features of'the invention will be particularly pointed out in the appended claims.

In describing the invention in detail, reference is had to the accompanying drawing, wherein I have illustrated a preferred physical embodiment of my invention, and wherein like characters of reference designate corresponding parts throughout the several views, and in which: I

Figure 1 is a diagrammatic view, partly in the nature of the wiring diagram, which shows the parts and electric circuits constituting one form of theinvention, said parts being illustrated more with a View of making their functions and operation clearly understood than with regard to their exact construction and arrangement; and

Fig. 2 is a fragmentary view showing some of the parts shown in Fig. 1, Fig. 2 being a section taken substantially on the line 2-2 in Fig. 1.

Referring to the accompanying drawing, the numeral 1 designates a portion of a track rall of the ordinary railroad track upon which the wheels of the vehicle run; and for s1mplicity only one of the wheels upon which the vehicle is supported is shown, this wheel being connected to the usual axle 3. According to the preferred embodiment of the invention illustrated in the accompanying drawing communication between the track and the vehicle necessary for the operation of the train control system is obta1ned by the mechanical and electrical cooperation of a contact shoe carried by the vehicle with ramps or contactrrails located at intervals along the track. The contact shoesmay be of any suitable construction; and for simplicity are shown diagrammatically in the accompanying drawing as comprising a vertically movable plunger 5, slidably mounted in a bracket 4 carried by'the vehicle, said bracket 4 for simplicity being assumed to be made of suitable insulating material. The shoe or plunger 5 is pro-- vided with a suitable foot or enlargement at its lower end which constitutes the rampengaging portion thereof; and said shoe is pressed downward'to its lower position, shown in Fig. 1, by a compression spring 7 interposed between a collar 6 fixed to said shoe and the under face of the bracket 4.

The shoe 5 is designed to open a circuit when lifted, and to perform this function is ,shown provided with a button 8 of insulatcent to one of the track rails so as to extend substantially parallel therewith and in the plane of the contact shoe. The electrical c0 from the ramp to the vehicle, subject to proper control in accordance with traffic conditions. The partial circuits associated with the ramp B may be of any suitable arrangement, and it is contemplated that these partial circuits will be controlled by the track relays of'certain track circuit sections into which the railroad track is divided in the usual manner; but, for .simplicity, these trackway circuits are not shown. The source of current associated with the ramp R is shown as comprising a transformer T, the primary 11 of which is connected to a transmission line or an alternating current generator of suitable construction. 7 One terminal of the secondary 12 of the transformer T is connected by a conductor 13 to the track rail land the other terminal of said secondary is connected by conductor 14, switch 15 and conductor 16 to the ramp R. It is apparent that this simplified arrangement provides a means for establishing a difference of potential between the track rail 1 and the ramp R equivalent to the voltage of the secondary 12, and for discontinuing this difference of mg the switch 15. r

The parts of the speed control apparatus are preferably in practice suitably supported in a box or casing F, a part of which is shown in the accompanying drawing, and affords a convenient means for supporting the various parts of the speed control apparatus.

The essential parts of the speed control apparatus are illustrated diagrammatically in the accompanying drawing,'and included in these parts is a speed indicator ST, which is connected to and driven by the wheels of the vehicle, and is so constructed as to indicate, by the movement given to a part or member, the changes in the speed of the vehicle. lln the simplified construction illustrated, a worm -17 is fixed to the axle 3, and meshing with said worm 17 is a worm gear 18 which is secured to the lower end of a shaft 19, said shaft 19 being journaled in suitable supports 20 and being provided with collars 21 pinned thereto, which are disposed above and below said supports 20 and serve to prevent endwise movement of potential by opensaid shaft 19. Fixed'to the shaft 19 by a pin 23 is a block 22; and loosely, mounted on the shaft 19 below the block 22 is another block 24. Connected to the ends of the block 22 are links 25 which are also pivotally connected to weighted balls 26; and, similarly connecting the block 24 to said balls 26 are links 27. A compression coil spring 28 is interposed between the two blocks'22 and 24. Journaled in any suitable supports (not shown) is a shaft 30 to which is keyed an arm 31 having its free end bifurcated; and supported by the bifurcated ends 32 of said arm are freely revoluble rollers 33, which are disposed between flanges 29 secured to or inte ral with block 24 of the speed indicator T. l The operation of the speed indicator ST is similar to that of the well known governor used for controlling the speed of engines, and will be. readily apparent without further explanation.

The device for indicating the permissive speed for the. vehicle at different points in its travel, which comprises a' cam, is also connected to the wheels of the vehicle, and in the arrangement shown in the. drawing this connection comprises a beveled gear 34 fixed to the shaft 19, which meshes with another beveled gear 35 fixed to the end of a shaft 36, which is supported in suitable bearing brackets on lugs 37 integral with or secured to the frame or casing F, said shaft 36 being provided with collars 38 pinned thereto and disposed on opposite. sides of the brackets 37, so as to limit the endwise movement of said shaft 36. Fixed to the shaft 36 is a. worm 39, which meshes with a gear 40 journaledon a bearing stud or pin 41 fixed to the casing F. A small gear 42 fixed to the gear 40 is also journaled on the pin 41 and meshes with the larger gear 43 journaled on a pin 44 also secured to the casing F; and fixed to the gear 43 is a small gear 45 which meshes with a larger gear 46. In a similar way intermeshing gears 47, 48 and 49 are journaled on bearing studs 50 and 51, and serve to complete a train of gears which will be readily recognized as the wellkno'w'n reduction gearing. Journaled atone end on the pin 51 is a lever 52 to which are rigidly fixed twopins 53 and 54; and mounted on said pins are two intermeshing gears 55 and 56, the gear 56 being also in mesh with the gear 49.

Disposed above the outer or free end of the lever 52 is'a cam control magnet C comprising two coils 57, the pole pieces of which are connected at their lower ends by the usual yoke 58, said yoke being bolted to lugs 59 integral with a wall of the casing F The armature 60 of the cam control magnet C is guided by pins 61 secured in the pole pieces of the coils 57; and this armature 60 is rigidly connected to a rod 62 which extends downwardly through an opening in the yoke 58 and is pivotally connected to the outer or' free end of the l6V8l"52. A collar: 63 is securely fastened to the rod 62. as byga;

pin, and interposed between the collar 63 and the yoke 58 is a compression coilspring.

64 which tends to move the rod 62 and the lever 52 to their upper position opposite to the position shown in Fig. 1.

J ournaled at one end in a boss 65 integral with one wall of the casing F is a cam-shaft at times when the lever 52 is in its upper,

position. Securely fastened to the cam-shaft 66, as by being pinned thereto, is a cam-shaped plate, hereinafter termed the cam 69. The factors determining the shape of this cam 69 will be pointed out more fully hereinafter. Also rigidly fastened to the cam-shaft 66, as by a pin, is an arm 70, the outer end of which is rounded and fits in a yoke formed by two fingers 71 on the outer end of one arm of an angle lever L, which is journaled on a stud or pin 72 integral with the casing F; and the other or vertical arm 73 of the angle lever L is arranged to make electrical contact with curvedcontact strips or segments 74, which are disposed on. opposite sides of said arm 73 with a slight space between them.

From the construction so far described it can be seen that a part of the system, namely, the shaft 30, is so arranged and connected that it assumes different positions or is displaced in accordance with the actual speed of the vehicle, and that another part, comprising the cam 69 and the cam-shaft 66, is

so arranged and constructed that it may be moved at times in accordance with the travel of the vehicle, and may be used to indicate the permissive speed for the vehicle at each point as determined by the shape of the cam 69. As indicated hereinbefore, the speed of the vehicle is controlled by the cooperation of the part which indicates the actual speed of the vehicle and of the part which indicates the permissive speed for the vehicle; and thiscooperation may be attained indifferent ways and may be utilized 'to act upon the brakes or other means used for controlli g the movement of the vehicle. In the construction andarrangement of parts illus-- trated, an arm 75 is fixed to the'shaft 30 and extends downwardly below the cam-shaft 66; and pivotally connected to the lower end of said arm 75 is the lower end of a floating lever 76, the upper end of which is provided with a freelyrevoluble roller 77 arranged to bear against the edge of the cam 69. A link 78 is pivotally connected at one end to the middle point of the floating lever 76, and at its other end to an arm 79 secured to a contact sector 80, which is journaled on a suitable shaft 81 supported by the frame or casing F. Integral with the casing F is a horizontal lug or bracket 82, which sup orts upper and lower contact carrying bloc s 83 and 84 of suitable insulating material; and supported by the blocks 83 and 84 are two contact supports 85 of the same construction which support contact fingers 86 and 91 and which also serve as binding posts. The contact finger 86 is formed with a pair of ears 87, which are connected by a horizontal pin 88 to one of the contact supports 85, this construction supportin the contact spring 86 so that it may be roc ed in a ver tical plane. The contact finger 86 is pressed in one direction, toward the left as viewed in Fig. 1, by a compression spring 89, mounted upon a pin secured to the corresponding contact support 85 in an obvious manner. Fixed to the left hand face of the contact spring 86 is a freely revoluble roller 90 of insulating material, which is arranged to bear against the. outer ed e of contact sector 80, as clearly shown in ig. 1. The contact finger 91 is su ilported on the other contact support 85 in t e same way as hereinbefore described in connection with the contact finger 86.

Normally, when the parts are in the position shown in Fig. 1, the contact finger86 is moved some distance to the right from its contact support 85 against the opposition of the spring 89, while the contact finger 91 is I anchored at the other end to the insulating block 83. I v

The cam-shaft 66 is provided with .an appliance for restoring it to its initial position after it has been turned by the gearing connecting it to the wheels of the vehicle.

As shown, this appliance comprises an arm 9i. journaled at its upper end on a pin or shaft 95, which is supported in lugs 96 integral with the top of the casing F, and this arm 94 is formed at itslower end with a toothed sector which meshes with a pinion 97 fixed to the cam-shaft 66. Also journaled on the shaft 95 are. two blocks 98, which are held against-endwise movement by a small pin 99 extending through the shaft 95; and integral with the up er end of the arm 94 is a laterally exten ing foot or lug 100, which is arranged to strike either of the blocks 98 as the arm 94 is rocked in one direction or the other. Extending loosely through each block 98 is a rod 101, the upper end of which is'pinned to a boss 102, integral with the top of the casing F; and encircling each roo 101 is a compression coil spring 103, one end of which presses against the corresponding block 98, and the other end of which bears against awasher or collar 104 held in place on said rod 101 by a small transverse pin 105 extending therethrough. v

According to the embodiment of the invention shown, it is contemplated that the speed of the vehicle will be retarded by the ordinary and well known system of air brakes; but since this system of brakes is well known in the art, no attempt has been made to show the construction and arrangement of its parts in detail. To better illustrate the application of the train control system embodying this invention to this system of air brakes, however, there is shown a portion 106 of the usual train pipe included. in said system of brakes together with a valve of simplified construction for opening communication between this train pipe and the atmosphere, and it is suilioient for a clear understanding of this invention to know that the opening of this valve and the venting of the train pipe 106 automatically causes an application of the brakes. As shown, the valve above mentioned comprises a casing 107, through which extends a plunger or rod 108, the lower end of said plunger 108 being formed with a valve 109 adapted to make an air tight joint with a suitable valve seat. Within the casing 107 is a compression spring 110, which bears against the valve 100 and tends to move it to its open position, whereby there is established the free communication between the train pipe 106 and the atmosphere which causes the application of the brakes. The upper end of the: rod 108.constitutes the core or plunger of a solenoid E, which. according to the arrangementv of controlling circuits shown and hereinafter described, is arranged to be normally energized so as to hold the valve 109 against its seat.

The speed control apparatus is governed electrically by a relay SC carried on the vehicle and hereinafter termed the speed control relay; and this relay SC is provided with two armatures or contact fingers 111 and 112, which are illustrated conventionally. The relay SC is in turn controlled by another relay P carried on the vehicle, and hereinafter termed the-pickup relay, and the relay P is provided with one armature 113.

Associated with the speed control apparatus and constituting one of the important parts of the improvement embodying this invention is a circuit controller K,

which is so constructed and arranged as to be operated electrically and to open after its controlling circuit has'been broken and after the lapse of a predetermined time.

This circuit controller K is shown in the accompanying drawing in a simplified form. as comprising a rod or plunger iii, to which. is secured and insulated therefrom a contact block or disk 115, said contact disk 115 being arranged to make electricalcontac-t with 'a pair of contact springs 116 for a portion of the movement of said plunger 114:. The upper end of the plunger 114;- constitutes the core of a solenoid 117; and the lower end of said plunger is connected to a piston 118 which is provided with a flexible packing and which is disposed within. a dashpot cylinder 119 having a small hole 120 in its lower end. The parts of the circuit controlling device K are shown in Fig. 1 in the normal position corresponding to the position which the partsassume when the controlling circuit for the solenoid 117 is closed, and in which the" contact 'disk 115 makes contact withthe contacting springs 116; and it will be readily apparent that when the solenoid 117 is deenergized, the plunger 114 will fall gradually by its own weight, at a rate determined by the rapidity of the escapement of the air from the dashpot cylinder 119 through. the hole 120; and that after the lapse of a predetermined time, depending upon the weight of the parts and the size of the hole 120, the plunger 11st will move downward to the point where the contact disk 115 moves out of electrical contact with the contact springs 116.

In order to provide the necessary electric current for operating and controlling the parts of the speed control system carried on the vehicle, a suitable source of current, herein shown as comprising two batteries A and B, is carried on the vehicle; but it is obvious that a single battery, motor generator or other source of current may be used, if desired v To determine the shape of the cam 69 involves a determination of the factors which affect the braking distance of the particular railroad equipment with which the cam 69 is associated. and which are dependent on the particular physical characteristics of the railroad over which the vehicle travels. The braking distance above mentioned for a railroad train is the distance in which that train may be brought to a stop by its brakes, and, as is clearly understood by those skilled in the art of braking trains, this distance not only depends upon the kind of braking equipment, but also upon the speed of the train at the time the brakes are first applied, upon the grade of the track over which the train is traveling while being stopped, the curves of this stretch of track, and other factors characteristic of this stretch of track which ailect the retarding efiect of the brakes. It is possible to determine what is known as the braking curve for a train when a particular kind of braking equipment and a given stretch of track are assumed, and this braking curve is a speed-distance curve which represents for each .point in the travel of the train, while its brakes are applied,

what the speed of said train will be at that point. shows how fast atrain can be moving at a given point in its travel over the assumed stretch of track, and yet be brought to a 'stop by its brakes before another predetermined point isreached. The shape of the cam 69 is determined from the braking curve ofthe train upon which this cam is mounted with reference to a certain stretch of track having a particular grade, curves, or the like. For instance, the cam 69 may be shaped to conform to the braking curve of the train for a level and straight stretch of track of a certain lengtln In practice, however, the different stretches of track or blocks, through which it is necessary to control the speed of thetrain, will not be of the same length, nor of the same grade, nor will their other physical characteristics, such as curves, be the same; and if it is desired, to control the speed of the train in these several blocks precisely in accordance with the braking curves of the train for these several blocks, it is apparent that it will be necessary to have a number of cams. For this reason it is contemplated according to this invention that a plurality of cams will preferably be used in the manner and for the reasons fully explained in my prior application above mentioned; but since this use of more than one camfforms no part of the present invention, there has been shown only one cam.

In the particular kind of cam illustrated,.

the lengths of the radii of said cam represent different speeds, and the angular'displacement of said cam from its initial position, as shown in Fig. 1, represents the different distances traveled by the train after the cam commences'to move. In efiect said cam represents a predetermined functional relation between the speed of the train and the distance traveled thereby, this functional relation being based upon the braking curve of said train for a given stretch of. track. The effective action of the cam 69 takes place along the path of movement of its follower, namely the roller 77 at the upper end of the floating lever 76. The manner in which the cam 69 cooperates with the speed indicator SI to control the speed of the vehicle will be more fully explained hereinafter in the description of the operation. In this connection it should be understood that while the shape of the cam 69 shown in the drawing illustrates in general the'shape of a cam which may be used In other words, this braking curve in practice, no attempt has beenmade to The parts of the speed control apparatus are shown in Fig. 1 in the osition which they assume when traffic cont itions are such that the train may travel at unlimited speed, there being, however, a limitation upon the maximum speed which the train may attain at any time, as explained hereinafter. When the parts are in this position, which may be termed the normal position, the speed control relay SC is normally energized by a circuit which may be traced as follows: commencing at one terminal of the battery A, conductor 121, coil SC, conductors 122 and 123, armature 111 of said coil in its upper position, conductor 1241;, contact v piece 10, contact spring 9, and conductors 125 and 126 back to the battery A.

The speed control relay SC by the pick-up relay P and said relay P is included in a partial circuit terminating at the contact shoe 5, and at the axle 3 of the vehicle, said partial circuit including conductors 127. and 128. When the pick-up relay P is energized in the manner hereinafter explained and its armature 113 is raised, another circuit for energizing ,the speed control relay SC is established and may be traced as followsz'commencing at one terminal of the battery A, conductor 121, relay SC, conductors 122 and 129, armature 113, of the relay P in its upper position, and conductors 130 and 126 back to the battery A.

With the speed control relay SC 'ener- 'gized and the armature 112 in its upper position, the cam control magnet C is energized by a circuit which may be traced as follows: commencing at one terminal of the battery B, conductors 131 and 132, armature 112 of the relay SC in its upper position, conductors 133 and 134, coils 57 of the cam control magnet O, and conductors 135 and 136 back to the battery B.

The solenoid 117 of the slow acting circuit controller K is also energized at this time by a circuit which may be traced as follows: commencing at one terminal of the battery B. conductors 131 and 132, armature 112 of the relay SC in its upper position, conductors 133 and 137, solenoid 117 and conductors 138 and 136 to the batte B.

The brake controlling solenoid is also energized at this time by a circuit which may be traced as follows: commencing at one terminal of the battery B, conductors 131 and 139, solenoid E, conductor 140, contact springs 91 and 86, conductors 141 and 142, contact spring 116, contact disk 115, contact spring 116 and conductors 1&3, 144 and 136 back to the battery B.

is governed There is another circuit for energizing the brake controlling solenoid E, which is closed when the cam-shaft 86 has been moved from its initial position through a small angle so that the arm 70 secured to said vcam-shaft has caused the movement of the angle lever L in one direction or the other, it being apparent from the drawing that by this movement of the angle lever L, a shunt path around the co-operating contacts of the slow acting circuit controller K is established, so that the solenoid E may he energized after the cam-shaft has moved through a. small angle, independently of the slow acting circuit controller K, by a circuit which may be traced as follows: commencing at one terminal of the battery B, conductors 131 and 139, solenoid E, conductor 140, contact'fingers 91 and 86, conductor 141, arm 73 of the angle lever L, one of the contact strips 74, along either conductor 145 or 146 to conductor 147, and thence by conductors 14A- and 136 back to battery 7 Maximum speed limitation.

Referring to Fig. 1, which shows the parts of the speed control system in the normal position, the actual speed of the vehicle at any instant is indicated by the movement of the arm 75, since this arm is connected to the shaft 30, which in turn is connected by the-arm 31 to the speed indicator S1. The lower end of the floating lever 76 is connected to the arm 75, so that the lower end of said floating lever is caused to assume different positionsx'according to the actual speed of the vehicle at that particular instant. Fig. 1' shows the arm 7 5 and the motor end of the floating lever 76 in the position corresponding to zero speed and as the speed of the vehicle increases, said lower end of the floating lever assumes positions more and more to the i left of the position shown; and it can be seen that if the cam 69 remains stationary so that the upper end ol the lever 76 also remains stationary, the speed of the vehicle cannot exceed a certain speed without moving the floating lever 76 so far to the left as to pull the link 78 and rock the contact sector 80 so far that the notch 92 in the edge of said contact sector is brought opposite to the roller 90, thereby permitting the contact finger 86 to move away fromthe contact finger 91 and interrupt both of the circuits hereinbefore traced tornormally energizing the brake-controlling solenoid E. Ob-

. viously, when the solenoid E isdeenergized,

the spring 110 opens the valve 109 and causes an automatic application of the brakes by venting the train pipe 10$.

By reason of this. construction and arrangement of parts the brakes are automatically applied in case the vehicle at any time exceeds the predetermined maximum speed determined by the shape of the cam 69. It

' of this warning signal and other features in conjunction with the speed control system illustrated, does not modify the action of the parts constituting the present invention, this warning signal and these other features have not been illustrated.

lVhen trailic conditions are such that a train may proceed by a ramp, such as the ramp R, and may travel through the block protected by that ramp at any speed less than the predetermined maximum speed, that is, in case trafi'ic conditions are such that a proceed signal will be displayed to the operator of the train, the switch 15 will be closed and a diiierence of potential will exist between the track rail 1 and the ramp ll. As thevehiole reaches the ramp R and itscontact shoe 5 engages said ramp, said contact shoe is raised sulhciently to separate the contact-spring 9 from the contact finger 10, thereby interrupting the normally closed circuit for energizing the speedcontrol relay SC. At the same time the partial circuit of the vehicle including the pick-up relay P is connected to the partial circuit associated with the ramp R, so that current is supplied to the relay P from the transformer T, the complete circuit for energizing the relay I being as :follows: commencing at the ramp R, contact shoe 5, conductor 127, relay P, conductor 128, axle 3, wheel 2, track rail 1, conductor 13, secondary 12 of the transformer T, conductor 1 1i, switch 15 in its closed position, and conductor 16 back to the ramp it.

In this .way, although one circuit for energizing the speed control relay SC is automatically broken by the engagement of the contact shoe 5 with the ramp R, the other circuit for said relay overned by the relay Mid the normally closed circuit for energizing the speed control relay SCis broken at said contact shoe, the pick-up relay P is maintained energized, and that when the co tact shoe leaves engagement with said ram the circuit "for normally energizing the relay SC is establishedhetore the other circuit con trolled by the relay P is broken. I

in case traflic conditions are such that the train approaching a ramp, such as the ramp ll, should so control its speed as to be brought to a stop or to a predetemined low speed by the time it reaches the end of the block protected by said ramp R, the switch R and the track rail 1. Under these COIldltions asv the vehicle passes the ramp R and its contact shoe 5 enga es therewith, the normally closed circuit or energizing the speed control relay SC is interrupted in the same way as hereinbefore explained; but, since the switch 15 is open, the relay P is not energized, and the relay SC is cut off from all current supply and its armatures drop.

The dropping of the armature 111 opens a break in the norm'all closed circuit for the relay SC, so that a er the contact shoe 5 leaves engagement with the ramp R, although one break in the circuit for normally energizingtherelay SC is closed at the contact shoe, nevertheless this circuit remains broken at the armature 1.11, thereby keeping the armatures of the rela SC in the lower position until the relay C is again energized by the relay P when the vehicle passes a ramp between which'and the track rail 1 a difference of potential exists. The dropping of the armature 112 of the relay SC 1nterrupts the circuits ,hereinbefore traced for energizing the cam control magnet C and the solenoid 117 of the slow acting circuit controller K. When the cam control ma not C is deenergized, the spring 64 pushes t e rod 62 upward, and raises the lever 52 so as to bring the gear 55 into mesh with the'gear 67,

whereupon the cam-shaft 66 is connected to the axle 3 of the vehicle and commences to turn, in one direction or the other, depend .ing upon the direction of the movement of the vehicle gradually and exactly in correspondence with the distance traveled b the vehicle. Upon the deenergization o the solenoid 117, the plunger 114 commences to move downward, but, as explained hereinbefore, a certain time must elapse before said-- plunger has moved far enough downward to break the connection between the contact disk 115 and the contact spring 116. Under normal conditions, when [the gearin connectin the wheel 2 of the vehicle with the cam shaft 66 is intact and operating properly, the camshaft 66 moves through a small angle sufiicient to operate the angle lever L by the arm 70 to close the shunt circuit, hereinbefore traced, before the time above mentioned required for the operation of the circuit controller K will elapse, thereby maintaining the solenoid E energized. In case, however,

some part of the gearing connecting the cam shaft 66 with the wheel 2 is broken or deranged in any way so that said cam-shaft does not commence to move upon the deenergization of the cam control magnet C, the angle lever L will remain in the position shown in Fig. 1', and after the ela ise of time required for the circuit controller to operate, the contact disk 115 will break electrical contact with contact springs 116 and intertrain progresses at a ratedepending upon the shape of the camv 69. The cam 69 is so shaped that as the vehicle progresses the upper end of the floating lever 76 assumes different gpsitions more to the left of thatshown in ig. 1, so as to correspond to the permissive speed of the vehicle at each point in its travel, determined by the braking curve of the vehicle for the particular stretch of track over which the vehicle is'then traveling. If it happens, and this is usually the case underordlnary conditions, that the vehlcle as it first passes the ramp R and when the cam control magnet C is first deenergized,

is traveling at a comparative high rate of speed, nearly as great as the maximum permissive speed, the lower end of the floating lever 76 will be moved by the arm 75 to a position such that the contact sector 80 isrocked downward to a position where the shoulder 92 is only av short distance from the roller 90. As the vehicle progresses and the cam 69 moves the upper end of the floating lever 76 more to the left, it is apparent that the lower end of said floating lever 76 must be moved to ,a corresponding extent to the right in order to prevent a further movement of the link 78 to the left far enough to bring the shoulder 92 in the edge of the contact sector 80 o posite to the roller and causean automatic application of the brakes; or, in other words, the actual speed of the vehicle must decrease at the same rate as the ermissive speed for the vehicle, determine by the cam 69, decreases, in order to prevent an vention, further explanation is deemed un-' necessary.

Referrin to the important features embodying this invention, it is apparent that the integrity of the gearing connecting the wheel 2 of the vehicle with the cam-shaft 66 is checked at each operation of the speed control apparatus and any failure of this gearing is Immediately detected and manifested by the automatic application of the brakes.

my invention, and explained the operation a and principle thereof; nevertheless, I desire to have it understood that the form selected is merely illustrative, but does-not exhaust the possible physical embodiments of the idea of means underlying my invention.

wheels thereof; a normally open circuit con- 1 allv What I claim as new and desire to secure by Letters Patent ofthe Unlted States, is:

1; In. a system for automatically controlling railway trains, in combination: means for controlling the movement of a vehicle adapted to be connected at times to a pair of 'trol-ler governed by said means and closed.

, after a small movement. thereof: a normally closed slow acting circuit controller; means for simultaneously controlling sa1d means and said-slow acting circult controller; aon- Jcuit controlled jointly by said circuit controllers arranged in multiple; and trafiic protecting means governed by said circuit.

2. in. a system for automatically controlling railway trains, in combination: a vehicle and a track therefor; means for determining the actual. speed of the vehicle; a cam for establishing the permissive speed for said vehicle; means governed jointly by said first means and by said cam for controlling the movement of the vehicle; gearing adaptcd'to operatively connect said cam at times to a pair of Wheels of the vehicle; a device for controlling said cam; a circuit on the vehicle for governing the movement thereof; means for opening said circuit after the lapse of a predetermined time subsequent to the operation of said device; and means governed by the movement of said cam for closing said circuit independently of said last mentioned means.

3. in a system for automatically controlling railway trains, in combination: a vehicle and a track therefor; a cam for governing the movement of the. vehicle; means for operatively connecting said cam at times to a pair of wheels of the vehicle; cooperating devices carried by the vehicle and arranged along the track for controlling said means and means for governing the movement of the vehicle which is set into operation at each operation of said first mentioned means unless said cam moves.

. lin a system for automatically control-,

incest? rendered effective after an initial change of said permissive speed device for preventing actuation of the safety appliance.

5. lln a system for automatically controlling railway trains, the combination with a vehicle, of a permissive speed device on the vehicle adapted to be connected to the wheels thereof at control points along the track when dangerous traffic conditions exist and to be moved gradually in accordance with the distance travelled by the vehicle, slowacting means also set into operation at said control points under dangerous tratlic conditions, and a safety appliance governed jointly by said means and by said permissive speed device and actuated eventually by said slow-acting means unless said perm1ss1've speed device has partially moved.

6. lln a system for automatically controlling railway trains, the combination with a vehicle, of automatic train control apparatus thereon comprising a permissive speed device adapted to change gradually to impose decreasing permissive speeds, a control relay on the vehicle for governing the operation of said device, a safety appliance, time controlled means tending to cause operation of the safety appliance after the lapse of an interval of time and also governed by said control relay simultaneously with said permissive speed device, and means controlled by said permissive speed device and acting after said device has partially changed for preventing operation of the safety appliance by said time controlled means.

7. In a system for automatically controlling railway trains, the combination with a vehicle, of automatictrain control apparatus thereon comprising a permissive speed device having its operation initiated at control points along the track when dangerous traffic conditions exist and adapted to chan e gradually during the progress of the vehicle to impose lower permissive speeds, and means including a time controlled device for automatically applying the brakeson the vehicl when said device fails to commence its change at a control point. v

8. In a system for automatically controlling railway trains, the combination with a vehicle, of a permissive speed device thereon adapted when set into operation to chan c gradually during the progress'of the vehic e so as to impose decreasing permissive speeds,

ildtl slow-acting means set into operation simultaneously with the initiation of the operation of said permissive speed device and tending to apply the brakes on the vehicle after a limited travel of .the vehicle, and means responsive to a change of said permissive speed device from its initial condition for preventing an application of the brakes by said slow-acting means.

9. In a system for automatically controlling railway trains, the. combination with a vehicle, of automatic train control apparatus thereon comprising a permissive speed device adapted to change gradually to impose decreasing permissivespeeds, a normally closed circuit, time controlled means for interrupting said circuit after an interval of time, means for setting the said permissive speed device and said time controlled means into operation at control points along the track when dangerous trafiic conditions exist, and means rendered efl'ective by a partial change of said permissive speed device for maintainin said circuit closed independently of said time controlled means.

10. In a system for automatically controlling railway trains, the combination with a vehicle, of a permissive speed cam having a tendency to assume an initial position, means adapted when set into operation to move said cam gradually against the opposition of said tendency so as to impose lower permissive speeds, a control relay for governing said means, a memberalso controlled by said relay andmovable to a final position.

independently of said cam, and a safety appliance jointly responsive to the movement of the cam from its initial position and to the movement of said member to its final position, said appliance being rendered active when said member assumes its final pos1t1on unless the cam has moved from its initial position.

11. In a system for automatically controlling railway trains, the combination with a vehicle, of a speed responsive device governed by the speed iof the vehicle, a permissive speed device set into operation at control points along the track under dangeroustraffic conditions and adapted to change gradually during the progress of the vehicle so as to impose decreasing permissive speeds, brake setting apparatus governed jointly by said speed desponsive device and said permissive speed device and acting to automatically apply the brakes on the vehicle when its actual speed exceeds the prescribed permissive speed, slow-acting means set into operation at the same time as said permissive speed device and adapted to change gradually to a final condition independently of said permissive speed device, said slowacting means in its final condition acting to cause operation of said brake setting apparatus, and means responsive to a partial change of said permissive speed device for preventing the operation of said brake setting apparatus by said slow-acting means.

12; In a system for automatically controlling railway trains, the combination with a vehicle, of a speed responsive device thereon governed in accordance with the actual speed of the vehicle, a permissive speed device adapted to impose varying permissive speeds during the progress of the vehicle, brake setting apparatus controlled jointly by said speed responsive device and said permissive speed device and operated when the actual speed of the vehicle exceeds the prescribed permissive speed, and means subjected to the same controlling influence as said permissive speed device for disclosing a failure of said permissive speed device toact after a limited travel of the vehicle.

13. In a system for automatically control-v ling railway trains, the combination with'a vehicle, of a permissive speed device thereon distance traveled by the vehicle, time controlled mechanism on the vehicle, a control relay governed at control points along the track in accordance with traffic conditions forv simultaneously initiating the operation of said permissive speed device and said timecontrolled mechanism; and a safety appliance governed jointly by the permissive speed device and the time controlled mechamsm.

adapted to change in accordance with the 14. In a system for automatically controlling railway trains, the combination witha vehicle, of automatic train control apparatus thereon having its operation initiated at control points along the track when danger oustraffic conditions exist", and automatic checking means subjected to the same controlling influence as said apparatus and actuated after the lapse of an interval 'of time unless said apparatus has operated.

15. In a system for automatically controlling railway trains, the combination with a vehicle, of a time controlled device thereon tending to apply the brakes after the lapse ofan interval of time, means for setting said device into operation at control points along the track under dangerous traffic conditions, automatic train control apparatus on the vehicle, and means for preventing the application of the brakes by *said time controlled device so long as said apparatus is 4 active to control the vehicle.

16. In a system for automatically controlling railway'trains, the combination with a vehicle, of a permissive speed device thereon adapted to change gradually during the progress of the vehicle so as to impose decreasing permissive speeds, means operated by a change of said device from its initial condition, and a safety appliance controlled by said means.

17 In a system for automatically controlling railway trains, the combination with a vehicle, or a permissive speed device thereon adapted to change gradually during the progress of the vehicle so as to impose decreasing permissive speeds, means forinitiating the operation of said device, and a safety appliance rendered effective each time the operation of said device is initiated unless it commences to change.

18. In a system for automatically controlling railway trains, the combination with a vehicle, of automatic train control apparatus thereon for restricting the speed of the Vehicle at diderent points in its travel when dangerous traiiic conditions exist, said apparatus comprising a movable element adapted to be moved in accordance with the travel of the vehicle, and means subjected to the same controlling influence as said element for disclosing when said element fails to move.

19. In a system for automatically control-- ling railway trains, the combination with a vehicle, of automatic train control a paratus thereon comprising a movable e ement biased to an initial position, means rendered active by a partial movement of said element from its initial position, control devices for initiating the movement of said element when dangerous traiiic conditions exist, and means governed by said control devices for disclosing when said means is not active.

. 20. In a system forautomatically controlling railway trains, the combination with a vehicle, of automatic train control apparatus thereon adapted to be placed in an active controlling condition to govern the movement of the vehicle at diiierent control points along the track, control devices partly on the vehicle and partly along the track for placing said apparatus in its active controlling condition, and checking means also governed by said control devices and ineluding a safety appliance actuated auto matically when said apparatus fails to respond and assume its active controlling condition.

21. In a system for automatically controlling railway trains, the combination with a vehicle, of a control relay thereon, means partly on the vehicle and partly on the track for governing said control relay in accordance with traiiic conditions, train control apparatus having its operation governed by said relay, and checking means also controlled by said relay and automatically assuming its active condition when said apparatus fails to operate.

22. In a system for automatically controlling railway trains, the combination with a vehicle, of automatic train control apparatus thereon comprising two separate devices both subjected to the same controlling influence and each adapted to change gradually to an ultimate condition independently of the other, and a safety appliance controlled by said devices and operated when one of said devices attains its ultimate condition before the other commences its change, whereby the operation of one device is checked by the other.

23. In an automatic train control system, automatic train controlapparat-us for railway vehicles, slow-acting means subjected to the same controlling'infiuence as said appa-v ratus, and checking means actuated automatically when the train control apparatus fails to operate before said slow-acting means. J

24. In an automatic train control system, automatic train control apparatus for railway vehicles, and means subjected to the same controlling influence as said apparatus for detecting a failure thereof to become active when controlled to do so, the action of said means being delayed sufiiciently to permit the train control apparatus becoming active when operating properly.

25. Automatic train control apparatus forrailway vehicles including a permissive" speed device adapted to change from a normal. initial condition, normally inactive means operated after said element has commenced its change from said initial condition, and means including said normally in active means and a device subjected to the same controlling influence as said element for detecting a failure of said element to commence its change when controlled to do so.

26. Car equipment for automatic train control systems comprising, a normally energized slow acting device tending to change to an ultimate condition, brake control means actuated when said device attains its ultimate condition, a normally closed circuit for energizing said device, train control apparatus, and means adapted to be conditioned from the trackway for interrupting said circuit and for governing the operation or said apparatus.

27. Car equipment for automatic train control systems com-prising a brake control device, a normally closed circuit including said device, time controlled means tending to change from. an initial condition to an ultimate condition and acting when in its ultimate condition to interrupt said circuit, means for normally maintaining the time controlled means in its initial condition. train control apparatus and a relay controlled from the trackway for governing the operation of said apparatus and for initiating the change of said time controlled means.

28. (ar equipment for automatic train control systems comprising, time controlled means effective to cause an automatic brake application after a time interval, other brake control apparatus adapted when open eluding means for closing one circuit con-' branch.

ating to prevent such brake application by the time controlled means and means governed from thetrackway for simultaneously initiating the operation ofxthe time controlled means and said other brake contrpl ap aratus.

29. ar equipment for automatic train control systems comprising, a brake control appliance, a governing circuit for said appliance including two multiple branches, automatic train control apparatus for actuating said appliance, a separate device subjected to the same controlling influence as said apparatus for breaking one of the multiple branches, and means for closing the other branch when said apparatus is acting.

30. Car equipment for automatic train control systems comprising, train control apparatus, a separate device set into operation at the same time as said apparatus, a brake control appliance. and an energizing circuit for said appliance having twobranches in multiple, said apparatus when operating closing one branch, and said device when operated opening the other 31.. Car equipment for automatic train control systems comprising a brake control appliance, two circuit controllers each ef-.

fective when closed to maintain said appliance inactive, train control apparatus in troller when the apparatus is operating, and means separate from said apparatus but subjected to the same governing influence for opening the other circuit controller when the apparatus is conditioned for operation.

32. Car equipment for automatic train control systems comprising train a control apparatus adapted to be conditioned for operation from the trackway, and automatic means including a device subjected to the same governing influence as said apparatus but operable independently thereof for determining when said apparatus fails to operate when conditioned for operation from the trackway. 33. Car equipment for automatic train control systems comprising, normally inactive train control apparatus including a movable element shifted when said apparatus is not in its active controlling condition, and means subjected to the same controlling influence as said apparatus for causing an automatic brake application when said element fails to shift.

34. In a train control system, speed governed brake control apparatus on a vehicle, means partly on the vehicle and partly on the track for controlling operation of said apparatus, and means for detecting failure of said apparatus to operate in response to the control thereof from the trackway, said means including the device subjected to the operation at the same time as said apparatus for causing an automatic brake application when the apparatus fails to operate.

36. In a train control system, train con trol apparatus on a vehicle, control means for said apparatus partly on the vehicle and partly on the track, slow acting means governed by the control means and set into operation at the same time as the said apparatus, said slow acting means when operated causing an automatic brake application after an interval of delay, and automatic means for preventing such brake application by the action of the slow acting means when the train controlapparatus is operating.

37. In a train control system, train control apparatus on a vehicle, a detecting device set into operation at the same time as the apparatus, and operable independently thereof, and automatic means responsive to the joint control of the apparatus and the detecting'device for causing a brake application when the apparatus fails to operate when conditioned for operation from the trackway. Y

38. In a train control system, train con, trol apparatus on a vehicle, changeable means assuming a' changed condition when said apparatus operates, a separate device operable independently of said apparatus and set into operation at the same time, a brake control appliance, and means for actuating said appliance upon operation of the separate device when said changeable means and means automatically rendered inactivebv the operation of said apparatus for preventing such brake application. by said detecting device. 7

40. In a train control system, speed governed brake control apparatus on a vehicle,

means partly on the vehicle and partly on the track for governing the operation of said apparatus in accordance with trafiic condi-' tions, slow acting means 0 erable independently of said apparatus ut governed by said means in the same way; said slow acting means when operated tending to cause an automatic brake application, and normally inactive means automatically rendered effective upon operation of said apparatus for preventing such automatic brake application.

41. In a train control system, control equipment comprising, a brake control appliance, speed governed mechanism inclnd ing a changeable device adapted when in its changed position to maintain said appliance inactive subject to the operation thereof at excessive speeds, and biased slow acting means having its operation automatically initiated at the same time as said apparatus and operable independently thereof, said slow acting means tending to operate the brake control appliance. after an interval of delay.

4L2. In a train control system, car-carried apparatus for governing the movement of the car and having its operation automatically governed from the trackway in accordance ,Wltll trailic conditions, said apparatus including normally inactive means changed when said apparatus assumes its active operating condition, and means whereby the brakes of the car are automatically applied upon failure of said means to change when the apparatus is conditioned for operation. from the trackway under dangerous traffic conditions.

43 in a train control system the combi nation with speed governed brake control apparatus on a vehicle, of automatic means for manifesting the failure of said apparatus to operate means for detecting failure in the operation of train control apparatus on railway vehicles comprising, a brake governing device subjected'to the same controlling influence as said apparatus but op erable-independently thereof,

44-. In a system for governing the movement of railway vehicles, apparatus on. a vehicle intermittently controlled from the trackway in accordance with traffic conditions, and automatic means for detecting failure of said apparatus to respond to the trackway control.

t. lln a train control system, the combination with a safety appliance on a vehicle, of independently operable train control apparatus and detecting means subjected to the same controlling influence from the trackway for exerting opposite governing influences upon said appliance.

V/ INTHROP K, HQWED 

